Various watercraft are commonly launched and hauled out at beaches and launch ramps by recreational boaters. At beaches, oversize tires or rollers facilitate these processes on the loose sand, but pulling the craft out of the water up the usual incline can be difficult since a land vehicle is unavailable for assistance because of poor traction in the sand.
At paved launching ramps, one generally has the boat on a trailer attached to a land vehicle (truck or automobile). Launching is generally easier than hauling out. One launches by backing down the inclined slope until the boat will float when it is rolled off the trailer. For hauling out, one backs down until the rear portion of the trailer is immersed and the bow can float onto the trailer rollers. Then the boat must be winched upward onto the trailer. Alternatively, with "float on" trailers, the trailer is backed down underneath the floating boat and boat and trailer are hauled out together by the vehicle.
Boat hauling out, therefor, requires backing the vehcle very close to the water' edge. After the boat is seated on the trailer, the entire load must be pulled up the incline. The incline surface often provides poor traction, being wet, covered with algae, sand, mud, and the like. Releasing the brake and simultaneously accelerating from a dead stop up a slippery slope without rolling backwards taxes the skills of the driver. After a boating excursion, the driver may be suffering the effects of fatigue, alcohol, and anxiety from pressures of others awaiting use of overcrowed public facilities. The effort may also overtax the power of the vehicle, causing it to stall and roll backwards. Consequently, many vehicles have rolled into the water with great financial loss. Seeing a vehicle rolling into the water prompts onlookers to misguided attempts to stop it, often resulting in personal injury. Some try to push or improve traction by climbing onto vehicle or trailer with resulting injury. Furthermore, overtired, overheated boaters may overexert in these stressful circumstances causing heat strokes or cardiovascular accidents.